Orange 'fire coloured'. Five objects, three in formation moving relatively quickly across the sky, all at the same speed and in the same formation. After maybe 30 seconds, they passed out of sight having faded somewhat. Two further objects of similar size and colour then followed, one after another. Travelling at similar speeds. The last one appeared to fade when travelling below an aircraft, then lit again and faded out. There was no noise from them and there was no noticeable shape (eg. they didn't look like hot air ballons).

Thy each moved at a uniform speed, the first three in a triangular formation, the last two individually.

We can not think of any plausible explanation.